A Michigan resident shows a water testing kit outside a water distribution location in Flint.
Photograph: Bryan Mitchell/The Guardian

A Michigan environmental official suggested a technician collecting samples for a suburban Detroit private water system “bump ... out” a test result that found very high levels of lead by testing more homes, according to a 2008 email reviewed by the Guardian. Doing so could avert a “lead public notice”, the email reasoned, which would alert residents of dangerously high levels in their water.

“Oh my gosh, I’ve never heard [it] more black and white,” said Marc Edwards, a Virginia Tech professor and lead expert who helped uncover the Flint water crisis. “In the Flint emails, if you recall, it was a little bit implied … this is like telling the strategy, which is: ‘You failed, but if you go out and get a whole bunch more samples that are low, then you can game it lower.’

“It just shows that this culture of corruption and unethical, uncaring behavior predated Flint by at least six years.”

Despite the email, residents in that jurisdiction were later notified of the high lead level.

The Chateaux Du Lac Condominiums, a homeowners association in Fenton, Michigan, operates on a private water system. Since its inception, records show, the association has struggled with high lead levels time and again. The system has exceeded federal lead action levels, set to trigger remediation efforts such as public education campaigns or expensive corrosion control, eight times over the past 20 years.

In early September 2008, a water laboratory technician collected samples from five of the nearly 45 homes in the association, the minimally required amount. The technician submitted the samples to the Michigan department of environmental quality for review. Of the five samples, one home registered a lead level of 115 parts per billion (ppb), nearly 10 times higher than the federal action level of 15ppb – and thereby put the Chateaux’s water system out of compliance.

On 16 September 2008, Adam Rosenthal, an MDEQ environmental quality analyst, sent an email to the technician to discuss the results. He copied Mike Prysby, the state employee who was criminally charged last week for his role in the city of Flint’s two-year lead contamination crisis, along with state employee Stephen Busch.

Prysby and Busch are accused by the Michigan attorney general of “improperly [manipulating] the collection of water samples” and removing “test results from samples to be included” in federal reports. (An attorney representing Prysby declined to comment, citing the ongoing criminal case.)

Adam Rosenthal, an MDEQ environmental quality analyst, sent an email to the technician to discuss the results. Photograph: Michigan.gov

“I just saw the results – 115 ppb for lead is a bit high,” Rosenthal wrote in the email. “Since this is an annual round of monitoring, which ends 9/30/08, there is still time to collect more samples and possibly bump this one out.”

Whether a system is in compliance with the federal lead and copper rule is dictated by what’s known as the 90th percentile level: if at least 90% of homes tested for lead register a level at or below 15ppb, the system is deemed in compliance with federal regulation.

Rosenthal suggested the technician could collect “a minimum of 5 more samples”. If five additional samples came in below 15ppb, the system would’ve remained in compliance.

“Since compliance is based on the 90th percentile, the 9th highest sample would count, 20 samples would be the 18th highest for the 90th, and so on,” Rosenthal said.

“Otherwise we’re back to water quality parameters and lead public notice.”

Chateaux still had to publish a public lead notice in 2008, and documentation shows that only five tests were performed, including the high test discussed in the email exchange.

Rosenthal did not respond to a request for comment, and a spokesperson for MDEQ declined to comment directly on the 2008 email.

“I understand that generally the department has always encouraged community water supply’s to sample early in the monitoring period to allow sufficient time to address any unforeseen issues that may arise (such as getting enough participants, lab turnaround time, etc),” spokesperson Melanie Brown said in an email. The federal lead and copper rule allows for continued sampling within a monitoring period to be used to calculate the 90th percentile, she said.

Experts said the email shows MDEQ’s Rosenthal was explicitly attempting to “subvert” the lead and copper rule.

Yanna Lambrinidou, a Virginia Tech faculty member who also helped expose Flint’s lead problems, described how collecting five more samples at Chateaux could have impacted regulatory oversight of the system under the federal lead and copper rule. “So if you collect 10 samples and you put them in order from lowest to highest, [if] the sample in position No9 is below 15ppb … then what that last sample is doesn’t matter for compliance purposes,” she said. “It could be 40,000ppb, but it still gives you compliance with the lead action level.”

“Of course, it’s alarming,” she said of Rosenthal’s email. She said the email could have “subvert[ed] the one and only regulation in the nation to protect us from lead in drinking water”.

Lambrinidou said Rosenthal’s email “is not about protection of public health” but instead protection of the utility.

Edwards pointed to a June 2015 email also written by Rosenthal, as Flint’s problem with lead began to emerge publicly. Then, Rosenthal wrote an email to Flint’s laboratory and water quality supervisor, Michael Glasgow, as well as the supervisor of the city’s water treatment plant, to discuss Flint’s current lead levels.

“We hope you have 61 more lead/copper samples collected and sent to the lab by 6/30/15,” Rosenthal said, “and that they are will be below the AL for lead. As of now with 39 results, Flint’s 90th percentile is over the [federal action level] for lead.”

Nearly a decade later, Chateaux has now submitted a corrosion control plan with MDEQ to help reduce lead, according to Mark Piper, the condominium project’s manager.

“The association has a community well,” Piper said. “The community well water does not have lead in the water. We are aware that a few of the houses tested above the recommended lead level. We submitted a corrosion control plan with the DEQ last year, per their guidance, and it was accepted by the DEQ.

“We are currently implementing the plan and will continue to monitor the water. Water sample test results that were completed in the past were shared with homeowners and the DEQ. Future test results will also be shared with the homeowners and DEQ.”

The most recent test for Chateaux showed its average lead level at 79ppb, the highest for private water systems in Michigan.

Despite the remediation efforts that have since been enacted at Chateaux, Lambrinidou said the 2008 email from MDEQ’s Rosenthal is troubling.

“Had his advice been heeded, a potentially serious contamination problem with very high levels of lead would’ve remained unaddressed,” she said, “And that the people would have not known anything about it while the … the state agency had full awareness.”

Given the water crisis in Flint, the 2008 incident suggests “a pattern,” she continued, with “not only how MDEQ was overseeing this regulation, but also potentially in how this regulation is being implemented elsewhere”.

“These types of actions can result in prolonged exposures to lead in water of fetuses, infants and young children whose lives are at stake,” she said.